1. Field of the Invention
The present invention is directed to the use of optical fibers capable of transmitting high density laser energy to internal body sites in microsurgery applications, thereby providing minimally invasive surgical techniques. The types of fibers used in these applications are referred to as side firing fibers, or simply side fibers, because they transmit the laser energy approximately perpendicular to the longitudinal axis of the optical fiber. The method of visual laser ablation prostatectomy (VLAP) has common application in the ablation of tissue in benign prostate hypertrophy (BPH).
2. Statement of Prior Art
Several attempts have been made at using laser therapy in the art of BPH. The following represents the state of the art:
In the article entitled, "Nd:YAG Laser Ablation of the Prostate as a Treatment for Benign Prostatic Hypertrophy", Costello, et al disclose a quartz fiber used to deliver laser energy via a gold-plated metal alloy tip containing a hollow deflecting device.
U.S. Pat. No. 5,292,320 to Brown et al. discloses a device capable of delivering high laser power at selected angles to the axis of the optical fiber.
Notwithstanding, the prior art which teaches numerous variations on the idea of the use of optical fibers in the art of laser ablation of tissue, none of the prior art teaches the system of the present invention involving a medical delivery optical fiber in which the distal tips have been modified to yield sideways directed radiation with high power densities at further distances from the fiber. This configuration enables non-contact ablation procedures to be accomplished with lower input laser power levels, and permits simpler, more compact and more economical laser sources to be employed.